Turbines are widely used in a variety of aviation, industrial, and power generation applications to perform work. Each turbine generally includes alternating stages of peripherally mounted stator vanes and rotating blades. The stator vanes may be attached to a stationary component such as a casing that surrounds the turbine, and the rotating blades may be attached to a rotor located along an axial centerline of the turbine. A compressed working fluid, such as steam, combustion gases, or air, flows along a hot gas path through the turbine to produce work. The stator vanes accelerate and direct the compressed working fluid onto the subsequent stage of rotating blades to impart motion to the rotating blades, thus turning the rotor and generating shaft work.
Higher working fluid operating temperatures generally result in improved thermodynamic efficiency and/or increased power output. However, higher operating temperatures also lead to increased erosion, creep, and low cycle fatigue of various components along the hot gas path. As a result, various systems and methods have been developed to provide cooling to the various components exposed to the high temperatures associated with the hot gas path. For example, some systems and methods circulate a cooling media through internal cavities in the components to provide convective and conductive cooling to the components. In other systems and methods, the cooling media may also flow from the internal cavities, through cooling passages, and out of the components to provide film cooling across the outer surface of the components. Although current systems and methods have been effective at allowing higher operating temperatures, an improved system and method for removing heat from the turbine would be useful.